Ultra-broadband,coherent mid-IR supercontinuum expanding from 1.5 to 12.2 μm in new design of AsSe2 photonic crystal fibre

We propose a new design of AsSe₂ photonic crystal fibre (PCF) with all-normal dispersion, nearly zero flat-top used to generate an ultra-broadband supercontinuum spanning from 1.5 to 12.2 μm. Simulated results show that, when we use only 1 mm of AsSe₂ PCF, a broadband mid-infrared supercontinuum with the specrum extent from 1.5 to 12.2 μm is obtained with a very low input energy of E = 1.3 nJ at the wavelength of 3.5 μm and pulse duration of 100 fs. We study the temporel and spectral impact of optical wave breaking in the development of the continuum. The influence of the fibre length, the input energy and the full width at half maximum is investigated. Compared to previous research works, we have obtained the broadest, coherent supercontinuum, which could be applicable in biomolecular sensing, cancer diagnostics, infrared spectroscopy and free space communication.     

佛手精油脂质体的制备及其抗氧化活性

以大豆卵磷脂和胆固醇作为壁材,采用薄膜分散-高压均质法制备佛手精油脂质体。以脂质体粒径、Zeta电位和包封率为指标筛选工艺参数和配方参数,确定脂质体最佳制备工艺,并对脂质体的形貌、稳定性进行考察,同时研究其抗氧化活性。结果表明,佛手精油脂质体的最佳制备工艺参数为:均质压力120 MPa、均质次数5次、磷脂/胆固醇比例5:1、精油添加量3.5 mg/mL。在此条件下制备的脂质体粒径为183.53 nm,PDI多分散指数为0.147,Zeta电位值为38.75 mV,包封率为47.23%,载药量为1.67 mg/mL。所制备的脂质体具有良好的离心稳定性、贮藏稳定性4℃贮藏30 d,精油保留率为85.03%,对DPPH、ABTS、羟基自由基的清除率分别为82.58%、78.02%、70.89%。结论:在均质压力120MPa、均质次数5次、磷脂/胆固醇比例5:1、精油添加量3.5mg/m L的条件下,制备的脂质体粒径适中、稳定性良好,具有良好的抗氧化活性。     

基于主体责任的公共部门建设管理研究

当前,关于基本建设项目主体责任的相关法规政策侧重于质量控制和安全监管。论文聚焦公共部门中建设单位主体责任落实,以人民银行为例分析建设单位在落实质量、安全主体责任时存在的问题或面临的困难,从责任矩阵、投资管理和绩效管理等三方面提出公共部门落实主体责任的若干措施。     

Impact of dam construction on the hydrological regime and quality of a Sahelian lake in the River Senegal basin

The direct and indirect impact of the recent hydraulic installations on the River Senegal on Lake Guiers are obvious. The hydrological regime of the lake was very irregular before the dams were brought into operation. The lake is now characterized by very stable water levels. These new conditions prevent cultivation of traditional recession crops which have been replaced by irrigated crops. The water quality of the lake has been modified. Mean salinity has decreased and the significant interannual and intraannual variations noted before 1986 are now far less pronounced. The new hydrological regime of the lake and its low salt content have encouraged aquatic vegetation to grow rapidly. This vegetation used to be controlled by the periodic partial drying of the flooding zone and specific water quality conditions at certain times of the year. Pistia stratiotes and Typha australis are now increasing rapidly. This proliferation of aquatic plants has no doubt accelerated the rapid spread of schistosomiasis, which now affects 80% of the population of some lakeside villages. The management of Lake Guiers requires an integrated quantitative and qualitative approach. A water management model has been perfected. It permits an assessment of the effects of various quantitative reservoir management options on the salinity of the water. © 1997 John Wiley & Sons, Ltd.     

Pervaporation separation of methyl tert-butyl ether/methanol mixtures using a high-performance blended membrane

For the separation of methyl tert-butyl ether (MTBE) and methanol mixtures, we investigated the pervaporation performance of a blend membrane made from cellulose acetate and cellulose acetate hydrogen phthalate. At first the influence of the blend composition was studied with a certain feed mixture. We found that all the tested membranes permeate methanol preferentially. The selectivity increases and the permeation rate decreases with increasing cellulose acetate content in the blend. Therefore, an optimal blend composition of 30 wt % in cellulose acetate was chosen to evaluate the influence of the feed composition and the experimental temperature on the pervaporation performance. When the feed temperature or the methanol content in the feed increases, the permeation rates are greatly enhanced and the selectivity decreases. However, the temperature effect is more significant at low methanol content in the feed and becomes negligible at high methanol content in the feed where plasticity effects prevail. A comparison, carried out with all the membranes until now used for the separation of MTBE/methanol mixtures, showed that the blended membrane studied in this present work presents good permselective properties. © 1997 John Wiley & Sons, Inc. J Appl Polym Sci 64: 875–882, 1997     

Sorption and pervaporation separation of ethyl tert—butyl ether and ethanol mixtures through a blended membrane

A new kind of membrane was prepared by blending poly(acrylic acid) with cellulose acetate propionate for the separation of ethyl tert—butyl ether and ethanol mixtures. The properties of the membranes were evaluated by the pervaporation separation of mixtures of ethyl tert—butyl ether/ethanol and the sorption experiments. The experimental results showed that the selectivity and the fluxes of this membrane depend on the blend composition and on that of processed feed mixtures. With respect to temperature, the ethanol fluxes obey the Arrhenius equation. The fluxes increase with the increase of the poly(acrylic acid) content in the blended membrane, the ethanol concentration in the feed, and the experimental temperature. But the selectivity decreases as the poly(acrylic acid) content and the experimental temperature are raised up. When the feed composition is varied, this membrane shows the special characteristics at the azeotropic composition. In the vicinity of the azeotropic point, the minimum values of ethanol concentration in the permeate and in sorption solution are obtained. The swelling ratios increase with an increase in the temperature and the ethanol concentration. The ethanol concentration in the sorption solution is also influenced by the temperature and composition of the mixtures. When the temperature increases, the sorption selectivity of the membrane decreases. © 1997 John Wiley & Sons, Inc. J Appl Polym Sci 66: 1631–1638, 1997     

考虑平衡三相负荷的低压配电网降损方案

针对低压配电网亟待解决的三相不平衡及技术降损问题,提出基于平衡三相负荷的解决方案。首先,介绍当前平衡三相负荷典型技术方案的原理,多维度对比不同技术方案的优缺点;在此基础上,通过数学推导和MATLAB数值仿真,分析平衡三相负荷对低压配电网电能损耗的影响及不同技术方案的降损效果;最终,基于广东地区三相不平衡现状,采用快速换相开关的技术方案。典型配电网台区治理后,平均三相不平衡度由40%下降至15%,技术线损降幅显著,验证了该方案节能降损效果明显,具有良好的操作性和经济性。     

HVDC附加次同步阻尼控制器设计及其相位补偿分析

附加次同步阻尼控制器(supplementary subsynchronous damping controller,SSDC)是解决由直流输电引起次同步振荡的一种有效措施.通过建立交直流系统发电机转速到电气转矩环节解耦传递函数结构分析了附加次同步阻尼控制器抑制次同步振荡原理,提出一种新型窄带通多通道SSDC结构及其相...     

Prevalence of antibodies to Rickettsia conorii Ricketsia africae, Rickettsia typhi and Coxiella burnetii in Mauritania

A 24-year-old male developed cytogenetic relapse of chronic myeloid leukemia (CML) four years after allogeneic BMT. After a year of treatment with IFN-alpha, he achieved a partial cytogenetic response. Treatment with donor leukocyte infusions (DLI) was given (total dose 1 x 10(8) T lymphocytes/kg). Two months later, he developed acute GVHD (skin and liver), that improved with CsA and methylprednisolone and resulted in cytogenetic remission with complete donor chimerism. One month later he developed rhinocerebral mucormycosis and was successfully treated with surgical debridement and liposomal amphotericin B (total dose 12 g). This is the first case of mucormycosis described after DLI.     

离网条件下的虚拟同步机分布式并联系统暂态稳定分析

虚拟同步机技术的应用,使得分布式电源具有同步发电机特性,可实现离网运行,其可控惯量对离网条件下分布式并联系统的频率稳定和有功振荡有很大的影响。基于离网条件下的虚拟同步机分布式并联系统,以两端输出有功功率振荡为标准,利用李雅普诺夫方法推导暂态能量函数,分析两端惯性时间常数对系统有功振荡的影响。根据分析结果,对暂态期间惯性时间常数进行控制,抑制有功振荡幅度,减小振荡时间,从而提高系统暂态稳定性。最后,利用PSCAD/EMTDC?软件建立模型进行仿真,验证所提方法的可行性。